Method of manufacturing base layer, ink for inkjet and electronic components

ABSTRACT

A base layer is formed on the surface of metal plate, metal pipe, unbaked ceramic sheet, laminated ceramic green sheet, etc., the base layer causing a gelling reaction with inkjet-ink. The base layer improves ink acceptability for low viscosity inks such as inkjet-ink, and prevents oozing, draining, uneven thickness of an ink pattern and a resist pattern. Thus, the present invention enables to use an ink jet process for providing resist patterns for etching, etc., which has to fulfill stringent high precision requirements.

RELATED APPLICATIONS

This application is a Divisional of U.S. patent application Ser. No.12/339,826, filed on Dec. 19, 2008, which is a Continuation-In-Part(CIP) of application Ser. No. 11/048,737, filed Feb. 3, 2005, nowabandoned, which is a Divisional of application Ser. No. 10/311,222,filed Mar. 21, 2003, now U.S. Pat. No. 6,855,367, which is a U.S.National Phase of International Application No. PCT/JP2002/003966, filedApr. 19, 2002, claiming priority of Japanese Application Nos.2001-122442, filed Apr. 20, 2001 and 2008-303972, filed on Nov. 28,2008, the entire contents of each of the foregoing applications arehereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method of manufacturing ceramicelectronic components such as ceramic parts, laminated ceramiccapacitors, LC filters, and composite high-frequency electroniccomponents. The method uses a computer-controlled ink-jet apparatus,which jets ink to form the foregoing various electronic components onnon-contact basis.

Further, the present invention enables a computer-controlled ink jetapparatus to form a high-precision pattern with least oozing anddropping of ink on the surface of low ink acceptability, such as metalsurface. Also on the surface of a three-dimensional substance, ahigh-precision pattern can be formed. Furthermore, on the surface of ametal pipe, for example, which exhibits low ink acceptability andthree-dimensional, a high-precision pattern can be formed with leastoozing and dripping. An ink pattern provided in accordance with thepresent invention can also be used for an etching resist. So, it can beused for manufacturing printers' magnet rolls and the like various typesof electronic components.

2. Background Art

A conventional method of manufacturing various ceramic electroniccomponents, first of all, prints a predetermined electrode pattern on anunbaked ceramic member such as a green sheet of ceramic by, e.g., screenprinting. Next, laminate the ceramic green sheets on which the electrodepatterns are printed, then cut the laminated sheet in a given shape, andbake them. Finally form external electrodes. Another method formsconductive or insulating patterns on an unbaked ceramic member, thenbake the member.

A conventional printing method such as a screen printing can formelectrodes in an identical shape; however, it is not good at formingelectrodes of different patterns, i.e., small batches of a variety ofproducts, or forming electrodes on non-contact basis, or formingelectrodes at a high speed. Japanese Patent Application Non-examinedPublication No. 2000-327964 and No. 2000-182889 disclose methods ofmanufacturing electronic components using inkjet for overcoming theforegoing problems. However, forming an electrode pattern using inkjetdepends on surface condition of a substrate on which the pattern is tobe printed. Thus some ceramic green sheet repels water or oil of ink,which produces non-uniform thickness of the printed pattern. As aresult, a desirable electrode pattern cannot be formed.

Problems of ink acceptability of those substrates to be printed aredescribed with reference to FIG. 11. FIG. 11A and FIG. 11B show anelectrode-shape required as a ceramic electronic component. Electrodepattern 1 shown in FIG. 11A has no pin-hole therein, and is required tohave a uniform thickness and to be a highly accurate fine pattern.Therefore, in FIG. 11B, electrode pattern 1 is formed on a ceramic greensheet on base film 2 in a uniform thickness.

FIG. 11C illustrates an electrode pattern formed with conventionalinkjet. As shown in FIG. 11C, the electrode patterns formed with inkjeton the ceramic green sheet are deformed due to repelling the jetted inkon the surface because the ceramic green sheet does not have inkacceptability. FIG. 11D is a sectional view of FIG. 11C and shows across section of the electrode patterns formed with the conventionalinkjet. As shown in FIG. 11C and FIG. 11D, electrode patterns 4 arerepelled and deformed, which is caused by poor wetness, namely, lowink-acceptability of the ceramic green sheet on which patterns are to beprinted. This is a similar phenomenon as a water drop is repelled on abase substrate which has been processed to repel water and oil. If suchan ink-repellant phenomenon occurs in an electrode pattern, pinhole 5tends to be formed inside electrode pattern 4. As a result, repelledelectrode pattern 4 ends up having non-uniform thickness.

As such, jetted ink landed on the surface of the substrate is deformedas shown in FIG. 11C and FIG. 11D because the viscosity of the ink is aslow as 0.01-0.1 poise and extremely subjected to surface tension of thesubstrate on which patterns are to be printed. Thus the landed ink isdeformed before the ink is dried or cured. In the case of screenprinting, on the other hand, the viscosity of ink is as high as severalhundreds poise, and the ink is hardly deformed. In a case of an inkjetprinter using papers available in the consumer market, since landed inksoaks into the paper, such uneven printing does not occur. However, inthe case of ceramic electronic component posed in the present invention,if jetted ink soaks into a ceramic green sheet, electrical insulation orreliability of a finished component is sometimes substantially degraded.Quick-drying of landed ink is one of measures against such a problem.However, quick-drying ink tends to dry and harden at a tip of a printerhead of an inkjet apparatus, and eventually clogs the printer head.Therefore, it is not good at producing stable print for long hours.

As discussed above, efforts have been made for printing givenelectrode-patterns accurately using inkjet; however, as shown in FIG.11C and FIG. 11D, irregular bumps and dips are formed in a sectionalview of electrode patterns, thus a required electronic component cannotbe produced.

An apparatus that forms a given three-dimensional structure using laserbeam is recently commercialized. This apparatus exposes photo-sensitiveresin to laser beam and cures the resin, and repeats this operationplural times before forming the given three-dimensional structure. Thefinished three-dimensional structure is formed of resin, therefore if itis sintered, an electronic component cannot be produced. If an electrodeor a member for forming an electronic component such as ceramic is addedto this kind of photo-sensitive resin, it becomes difficult to cure thissubject with light.

Japanese Patent Application Non-examined Publication No. H02-415702discloses a method of forming a three-dimensional structure usinginkjet. This method deposits a first layer of powder material at alimited area, then deposits binder at a selected area of the powdermaterial layer, so that the bound powder material is formed at theselected area before a component is produced. This method repeats theforegoing operation selected number of times for producing a givenplastic component. Thus a successive layer is formed at the selectedarea of the bound powder material. Then un-bound powder material isremoved, whereby a three-dimensional structure is formed. However, inthe case of the disclosure discussed above, the inkjet apparatus jetsbinder for powder, and the binder does not include the powder. When thethree-dimensional structure is taken out, surplus powder should bebrushed off. Further, this disclosure has difficulty for forming athree-dimensional structure including plural members such as ceramic,electrodes and so on, which are necessary for an electronic component.

SUMMARY OF THE INVENTION

A base layer described in a method of manufacturing base layer, ink forinkjet and electronic components in accordance with the presentinvention contains at least 0.01 weight % of a component, which reactswith an additive component of organic substance included in the ink tocause gelling, and burns off at a temperature not lower than 300° C.

An ink for inkjet apparatus described in a method of manufacturing baselayer, ink for inkjet and electronic components in accordance with thepresent invention contains at least 0.01 weight % of a component, whichreacts on additive component of organic substance included in base layerto produces gelling, and burns off at a temperature not lower than 300°C.

A method for manufacturing electronic components described in a methodof manufacturing base layer, ink for inkjet apparatus and electroniccomponents in accordance with the present invention is a method ofmanufacturing electronic components using an inkjet apparatus, themanufacturing method includes the steps of improving the surface ofprinting object by providing the surface with a base layer in order tomake the surface to be ink acceptable, and forming a certain specificpattern on the base layer by applying the ink with inkjet apparatus. Atleast either one of the base layer and the jet-ink contains a compoundwhich produces gelling through a chemical reaction or a mutual reaction.

The above-described method of manufacturing a base layer, an ink forinkjet apparatus and electronic components in accordance with thepresent invention offers a substantial advantage in the production ofelectronic components, among other industrial sectors.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A shows a sectional view of formation of an electrode pattern on abase layer in accordance with a first exemplary embodiment of thepresent invention.

FIG. 1B shows a sectional view of the formation of the electrode patternon the base layer in accordance with the first exemplary embodiment ofthe present invention.

FIG. 1C shows a sectional view of the formation of the electrode patternon the base layer in accordance with the first exemplary embodiment ofthe present invention.

FIG. 2A shows a perspective view of an electrode pattern with a baselayer and that without a base layer.

FIG. 2B shows characteristics of the electrode pattern with the baselayer and that without the base layer.

FIG. 3A shows a sectional view illustrating an electrode pattern with abase layer and that without a base layer due to drying.

FIG. 3B shows a sectional view illustrating an electrode pattern with abase layer and that without a base layer due to drying.

FIG. 3C shows a sectional view illustrating an electrode pattern with abase layer and that without a base layer due to drying.

FIG. 4A illustrates a status when a printer discharges a sheet.

FIG. 4B illustrates a status when a printer discharges a sheet.

FIG. 4C illustrates a status when a printer discharges a sheet.

FIG. 5 illustrates that solvent contained in ink soaks into a baselayer, whereby the ink is set.

FIG. 6 illustrates that solvent contained in ink soaks into a baselayer, whereby the ink is set.

FIG. 7 illustrates a case where gelling reaction is used.

FIG. 8 illustrates a case where reaction between organic components.

FIG. 9 illustrates a case where reaction between inks thereby forming athree dimensional structure.

FIG. 10 illustrates a sectional view of a three dimensional structureformed in an exemplary embodiment of the present invention.

FIG. 11A shows a plan view of a required electrode pattern.

FIG. 11B shows a sectional view of the required electrode pattern.

FIG. 11C shows a plan view of an electrode pattern formed by aconventional method.

FIG. 11D shows a sectional view of the electrode pattern formed by aconventional method.

FIG. 12A shows a perspective view of a metal pipe which is a material ofa magnet roll to be applied of the base layer according to an exemplaryembodiment of the invention.

FIG. 12B is a perspective view showing the metal pipe coated at thesurface with the base layer.

FIG. 12C is a perspective view showing how a pattern is printed bydroplets jetted from an inkjet apparatus.

FIG. 13A is a sectional view showing how the inkjet apparatus jets thedroplets for the printing.

FIG. 13B is a sectional view showing that the droplet jetted from theinkjet apparatus lands on the base layer to form a resist pattern.

FIG. 13C is a perspective view showing the state after the base layer isremoved.

FIG. 14A is a cross sectional view showing a state after the surface ofthe metal pipe is etched with the resist pattern used as an etchingresist.

FIG. 14B is a cross sectional view showing how the resist pattern isremoved.

FIG. 14C is a perspective view of the metal pipe provided at the surfacewith recesses to form a certain specific pattern.

FIG. 15A is a cross sectional view of a recess used to show how tonerand a carrier slip on a smooth surface.

FIG. 15B is a cross sectional view used to describe how toner and acarrier are held retained without slipping on a roughened inner wallsurface of a recess according to an exemplary embodiment of theinvention.

DETAILED DESCRIPTION OF THE INVENTION Exemplary Embodiment 1

In this embodiment, formation of an electrode pattern onto a ceramicgreen sheet is demonstrated. FIG. 1A-FIG. 1C illustrate a method offorming an electrode pattern on the surface of a ceramic green sheethaving a base layer. FIG. 1A shows a sectional view illustrating amethod of forming a given electrode pattern by inkjet method on aceramic green sheet having a base layer. FIG. 1B shows the givenelectrode pattern thus formed. In FIG. 1A inkjet apparatus 7 is loadedwith predetermined ink, and jets droplet 8 responsive to an externalsignal. The external signal can adjust not only jetting of droplet 8 butalso a size (volume, quantity and diameter) of droplet 8. On base film2, ceramic green sheet 3 is formed, and on top the surface of sheet 3,burn-off base layer 11 that is a feature of the present invention isformed. According to the present invention, plural droplets 8 jettedfrom inkjet apparatus 7 land on burn-off base layer 11 and form a givenelectrode-ink-pattern 1.

An example of the electrode pattern thus formed on the ceramic greensheet is shown in FIG. 1B, in which electrode pattern 1 free from oozingis accurately formed as the design requests. FIG. 1C is a sectional viewcut along a line at anyplace in FIG. 1B. As shown in FIG. 1C, electrodepattern 1 according to the present invention is formed in an uniformthickness on burn-off base layer 11.

Burn-off base layer 11 of the present invention is formed on the surfaceof ceramic green sheet 3, whereby droplet 8 after it landed on greensheet 3 is not flowed or repelled due to the gravity or the surfacetension (the surface tension of the surface of ink, the surface tensionof the base layer.) Burn-off base layer 11 of the present invention isburnt off in a baking step prepared later and disappears, so that itdoes not adversely affect the reliability of the finished electroniccomponent.

To be more specific about the foregoing method, ceramic green sheet 3used in the first embodiment is formed by applying ceramic slurry ontoresin film such that the solid content of the slurry becomes a thicknessof several microns. The ceramic slurry is produced by mixing anddispersing ceramic powder, of which temperature characteristic shows Bof EIAJ standard, and made of mainly barium titanate into mixed solutionincluding butyl acetate, phthalate plasticizer, and butyral resin.

Next, an inkjet apparatus available in the consumer market prints thegiven electrode pattern 1 with commercial water soluble black ink on theceramic green sheet 3. The result is shown in FIG. 11C. The ink lands onthe ceramic green sheet and is repelled immediately like beads of water.As a result, target electrode pattern 1 cannot be formed. This isbecause the ceramic green sheet is not hydrophilic, and the watersoluble ink landed does not soak into the surface of the sheet, but theink is repelled by the surface tension of the base layer.

Thus water soluble resin is used as burn-off base layer 11, and theresin is dissolved in water and applied to the ceramic green sheet suchthat a dried thickness becomes 0.5 micron. In this embodiment,commercially available polyvinyl acetal (e.g., KW1 or KW3 manufacturedby Sekisui Chemical Co. Ltd.) is used as water soluble resin. Acommercially available inkjet apparatus jets the commercially availablewater-soluble black ink onto ceramic green sheet 3 on which burn-offbase layer 11 is formed. The result is shown in FIG. 1B, i.e., accurateelectrode pattern 1 free from deformation is obtained. Thus hydrophilicburn-off base layer 11 prepared on the poorly hydrophilic (highly waterrepellent) ceramic green sheet can prevent electrode pattern 1 frombeing deformed using water-soluble ink.

For the comparison purpose, the same test is done using a ceramic greensheet formed of water-soluble resin. Water-soluble polyvinyl acetalresin is dissolved in water, glycol (plasticizer), and alcohol (foradjusting a drying speed) to produce solution of water-soluble resin.The foregoing ceramic powder is mixed and dispersed into this solutionto produce ceramic slurry. An applicator applies the slurry onto resinfilm such that a thickness of the slurry becomes several microns. Thegiven electrode pattern 1 is printed on the surface of the slurry withthe water-soluble black ink available in the market, then thewater-soluble ink not only dissolves the water-soluble ceramic greensheet, but also deforms the electrode pattern, an eventually makes holeson the ceramic green sheet.

In other words, water-soluble jetted ink is repelled on the ceramicgreen sheet of non water-soluble, and water-soluble jetted ink on thewater-soluble ceramic green sheet dissolves the sheet.

On the other hand, when non water-soluble (i.e., poorly ink acceptable)ceramic green sheet demonstrated in this embodiment is equipped with athin hydrophilic burn-off base layer 11 on its surface, the green sheetobtains ink acceptability for water-soluble jetted ink and prevents thejetted ink from soaking into the sheet.

Next, a trial product of ink supposed to be used in an inkjet apparatusis employed in a similar experiment. The ink is made of nickelparticles, which is turned into jet-ink using a method of manufacturingwater-soluble ink, the method is disclosed in Japanese PatentApplication Non-examined Publication No. H11-102615. The ink thusmanufactured is used for printing on both surfaces of ceramic greensheet 3 and burn-off base layer 11 provided on top of sheet 3 usinginkjet apparatus 7. On the sheet 3 of non water-soluble, the ink isgreatly repelled and deformed due to water repellency of the surface. Ifwater-soluble ceramic green sheet is used, the ink dissolves the sheet.On the other hand, on the surface of the burn-off base layer, the ink isnot repelled but formed into a uniform thickness accurately. Being leftfor long hours, the ink keeps its pattern free from deformation.

Prepare several hundreds of ceramic sheets, each having burn-off baselayer on which electrode pattern 1 is formed, then laminate 300 sheetssuch that electrode pattern 1 shifts by a given distance. Cut the 300sheets into squares of 2.5 mm×1.6 mm size, then bake the cut pieces, andfinally form electrodes to complete laminated ceramic capacitors. Thelaminated ceramic capacitor thus manufactured is excellent in bothinitial properties and reliability. A scanning electron microscopecannot observe burn-off base layer 11 on a cross section of thiscapacitor, because the base layer of the present invention is burn off.The burn-off base layer made of mainly burn-off material such as resinis burn off and volatilized during the baking, and does not remain inthe finished electronic component, thus the base layer does notadversely affect the finished product.

In a case of forming burn-off base layer 11 of only resin, the thicknessof the base layer is preferably not more than 20 microns, and morepreferably it is not more than 5 microns. If the thickness of burn-offbase layer 11 made of mainly resin is not less than 20 microns,defectives such as inter layer peeling occur in some products. Adding aceramic member inside burn-off base layer 11 is effective to prevent theinter layer peeling.

Exemplary Embodiment 2 Advantage of Reducing Unevenness

In the foregoing first embodiment, it is demonstrated that electrodepattern 1 is formed on the ceramic green sheet on which burn-off baselayer 11 is prepared. In this second embodiment, it is demonstrated thatuneven thickness of electrode film applied depends on the presence ofburn-off base layer 11.

FIG. 2A illustrates a case where burn-off base layer 11 is formed ononly parts of the surface of ceramic green sheet 3. The advantage ofburn-off base layer 11 is described using FIG. 2A, which shows a uniformthickness at an area where burn-off base layer 11 is formed and greatlyuneven thickness at electrode patterns 4 formed directly on the ceramicgreen sheet without base layer 11. FIG. 2B shows the thicknesses ofelectrode patterns 1 and 4 shown in FIG. 2A measured with fluorescentX-ray. In FIG. 2B, the X-axis represents pattern widths (mm) and theY-axis represents applied amount of Ni per unit area (mg/mm²). The spotdiameter of the fluorescent X-ray is 0.1 mm which increases resolutionin measuring. In FIG. 2B, black circle ● indicates the electrode patternwith the burn-off base layer proposed by the present invention andcorresponds to electrode pattern 1 shown in FIG. 2A. In FIG. 2B, whitecircle ◯ indicates the electrode pattern without burn-off base layer 11and corresponds to electrode pattern 4 with uneven thickness shown inFIG. 2A.

As shown in FIG. 2B, in the case of burn-off base layer 11 of thepresent invention being available, an uniform thickness is obtainedoverall the pattern. On the other hand, in the case of burn-off baselayer 11 being not available, a little amount of Ni is applied aroundelectrode pattern 4 but a greater amount of Ni is applied at the centerof electrode pattern 4. Thus substantially uneven application isobserved in the axial direction.

Next, the uneven application discussed above is detailed using FIG. 3,which monitors drying procedure of electrode patterns 1 and 4 shown inFIG. 2A with sectional views. On the left sides (burn-off base layer 11is available) of FIG. 3A-FIG. 3C, a droplet (not shown) jetted from aninkjet apparatus (not shown) lands on burn-off base layer 11 and formspattern 1 as shown in FIG. 3A, and solvent component in the ink isvolatilized with a lapse of time. Then the ink is gradually dried andthinned keeping the uniform thickness and the shape shown in thesectional view as shown in FIG. 3B and FIG. 3C.

On the other hand, in the right area where burn-off base layer 11 is notformed, a droplet (not shown) landed on the ceramic green sheet of waterrepellency is repelled as if a bead of water, as shown in FIG. 3A, dueto the water repellency of the surface. Its cross section shows a riseat the center. A peripheral section where the thickness of electrodepattern 4 is the thinnest among other sections starts volatilizing, andother sections follow. The center section having the greatest thicknessremains escaping being dried to the end. At this time, the ink in liquidcondition (not dried yet) is pulled by the surface tension to the centersection, thus cracks 12 and pinholes (not shown) tend to occur betweenthe peripheral and center sections. Electrode pattern 4, where such anuneven thickness occurs, is not suitable for manufacturing electroniccomponents of high performance required from the market.

Next, a phenomenon, in which solvent component in the ink soaks into theburn-off base layer, is explained as follows: FIG. 5 and FIG. 6illustrate that the solvent component in the ink is absorbed in theburn-off base layer thereby setting the ink. In FIG. 5, droplet 8 jettedfrom the inkjet apparatus (not shown) lands on burn-off base layer 11and forms landed droplet 13. At this time, some solvent component out ofdroplet 8 soaks into base layer 11 along the arrow marks. FIG. 6A andFIG. 6B show a printing procedure. In actual, thousands or millions ofdroplets 8 per second are jetted from the inkjet apparatus (not shown),and landed droplets 13 are piled up on the sheet as shown in FIG. 6A toproduce a given thickness. In this case, some solvent component fromplural landed droplets 13 are absorbed into base layer 11 along thearrow marks. Landed droplets 8, from which some solvent is removed,increase their viscosity and are integrated with each other to formelectrode pattern 1 shown in FIG. 6B. In a case of printing on a regularpaper with the inkjet, the ink is completely absorbed into the paperbecause the ink is dye ink. However, according to the present invention,ink including powder material is used and the sheet has low absorptionof ink. In such a case, a highly accurate pattern is obtainable onlyafter the burn-off base layer is formed, which is proposed by thepresent invention.

Exemplary Embodiment 3

In the foregoing second embodiment, reducing uneven thickness usingburn-off base layer 11 is described. In this third embodiment, uneventhickness of an applied film is further reduced using chemical reactionbetween burn-off base layer 11 and ink. In this embodiment, the burn-offbase layer contains organic carboxylic acid.

First, as the material of burn-off base layer 11, employ anionicpolyvinyl alcohol resin (manufactured by KURARE Inc.), and dissolve theresin in pure water. Then apply the resin dissolved in the pure wateronto ceramic green sheet 3 such that a thickness of dried resin becomes0.5 micron. Burn-off base layer 11 of anion resin is thus formed.

Next, as the material of ink, dissolve nonionic polyvinyl alcohol resinmanufactured by KURARE Inc. in pure water. Then add some nonionicdispersant, nonionic plasticizer (glycerin, polyethylene glycol areused) and Ni powder to the resin dissolved in the pure water. Nonionicink is thus produced. Load the nonionic ink into a printer (made byEPSON Inc., model No. MJ510C) and print patterns in 720 dpi. FIG. 4illustrates this printing. In FIG. 4C, the ceramic green sheet on whichelectrodes are printed is discharged from the printer in a slantedmanner, so that the ink flows in the electrode pattern and uneven printtends to occur.

In this third embodiment, electrode pattern 1 is formed on burn-off baselayer 11; however, uneven print due to the ink flow does not occur.Because at the instant when nonionic ink lands on anionic burn-off baselayer 11, a kind of gelling reaction between nonion component in the inkand anionic base layer 11 starts, which prevents the landed ink fromflowing.

This situation is detailed with reference to FIG. 4. As shown in FIG.4A, burn-off base layer 11 is formed on the left half of ceramic greensheet 3, on which electrode patterns are to be printed. Inkjet apparatus7 prints given electrode patterns on sheet 3 at both the areas, one hasbase layer 11 and the other does not have. FIG. 4B shows electrodepattern 1 printed on burn-off base layer 11, where the ink does notdrain although sheet 3 is held vertically with the ink still wet. Inother words, non-uniform thickness does not occur. FIG. 4C, on the otherhand, shows a status without burn-off base layer 11, where the ink ofthe patterns drains downward when sheet 3 is held vertically with theink still wet.

In the case of using the burn-off base layer made of nonionic resin, thesame material as the ink, the ink is formed accurately; however, apattern formation by the inkjet apparatus onto the base layer causes theink to drain in the pattern as shown in FIG. 4C. This phenomenon occurswhen an electrode pattern still wet is placed vertically as shown inFIG. 4A or the ink is jetted onto the sheet vertically held. Then theink drains in the pattern due to its own weight or non-uniform thicknessoccurs in the pattern. On the other hand, in the case of using theburn-off base layer made of anionic resin, a pattern formation on to thebase layer does not cause the ink to drain in the pattern or non-uniformthickness does not occur in the pattern, although an electrode patternstill wet is placed vertically or the ink is jetted onto the sheetvertically held.

According to the present invention, reaction between a componentincluded in the burn-off base layer reacts and a component included inthe ink allows the pattern formed on the base layer to keep its shapeaccurately before the solvent component volatilizes. In other words,even if the wet ink landed on the burn-off base layer is put in a drierand blown by volume hot air at a high speed, the printed pattern or itscross sectional shape is not adversely affected. Thus the manufacturingmethod of the present invention allows a drier to be placed inconjunction with the inkjet apparatus, and this structure can save themanufacturing equipment a lot of space.

A use of the advantage of the present invention in commerciallyavailable and high-speed inkjet printers, which employ varioushigh-speed heads, allows jet-ink used for various electronic componentsto be dried free from adverse influence to their cross sectional shapes.The advantage is applicable in a high speed printing such as severalmeters per minute or several-hundred meters per minute. Since thepresent invention can print electrode patterns free from uneventhickness on a sheet held vertically, a floor space for the printingapparatus can be reduced, and the printing apparatus can be integratedinto another apparatus with ease. This advantage allows simplifying theapparatus, lowering the cost, and providing a clean room with ease. As aresult, finished products can be manufactured at a reasonable cost andthe yield ratio can be improved.

As discussed above, the material added to the ink and the material addedto burn-off base layer 11 contact with each other to start gellingreaction, thereby curing the ink instantaneously. High strength of curedink is not required in this curing reaction, but soft curing or gellingthat can prevent the ink from draining is good enough. A combination ofthe two materials is, e.g., anionic material with nonionic material,anionic material with cationic material, nonionic material with cationicmaterial. Reactions between those materials are described as a reactionbetween a donor and an acceptor in the fourth embodiment and onward.

The present invention finds that the dispersant can be used for startingthe gelling reaction. For instance, polycarboxylic acid based dispersantof anionic material, made by KAO inc. or SUN-NOPCO and available in themarket, is used for producing ink, and nonionic resin is used as theburn-off base layer. In this case, a similar reaction to what isdiscussed above can be expected. This chemical reaction is consideredsimilar to the gelling reaction proper to water-soluble resin, i.e., thegelling reaction between polyvinyl-alcohol-based synthetic starchavailable in the market being mixed with borax. Materials such as boraxcontaining sodium or boric acid leave residual component, which affectsreliability of the electronic component, after the material is baked.Therefore those materials are not good for burn-off base layer 11 of thepresent invention.

It is desirable to use organic acid or organic base which does notproduce residual component after the baking for realizing themanufacturing method of the present invention. Several ten thousands ofsuch organic substances are known in the world, and an ordinarilyskilled person in the organic chemistry can optimize those materialswith ease. According to the experiments by the inventors, an organicacid which includes at least carboxyl group (—COOH) is useful from theview point of reliability.

Resin including carboxylic acid is used as either one of the ink or theburn-off base layer, and resin or organic substance of cationic ornonionic one is used as the other one (base layer or ink), whereby thegelling reaction can be produced. Any organic compound R—COOH havingcarboxyl group can be the resin containing carboxylic acid where Rrepresents hydrocarbon group and can be used for the present invention.

This reaction is considered similar to a kind of salt out reaction. Inthe present invention, in the case of producing metal salt, such assodium, of alkaline material or alkaline earth material, residuals afterthe baking sometimes affect adversely to reliability. Thus additioncompound of organic base and acid, or organic substance is preferablyproduced instead of metal salt from the salt out reaction.

Besides ceramic member in the burn-off base layer, conductive powder ormagnetic powder can be added, so that the base layer becomes morefunctional. For instance, the materials proposed here to be used in theburn-off base layer can be added to the ceramic slurry which is thematerial of a ceramic green sheet or an unbaked ceramic member. In otherwords, the material supposed to react on the ink is added to the ceramicgreen sheet or unbaked ceramic member in advance, so that a ceramicgreen sheet having higher ink-acceptability can be produced.

In the present invention, the ink preferably has a viscosity of lessthan 2 poise. In the case of viscosity not less than 2 poise, an inkjetapparatus available in the market clogs sometimes with the ink. The bestway to prevent the inkjet apparatus from clogging is to dilute the inkwith water-soluble solvent such as water or glycol; however, the thinnerink tends to produce uneven print on the sheet. The manufacturing methodof the present invention uses chemical reaction between the sheet andthe ink, therefore, even if the ink is diluted, uneven print can besuppressed, and the ink can be dried fast.

Exemplary Embodiment 4

In this fourth embodiment, the gelling reaction, produced by landing thejet-ink on the burn-off base layer, is described with reference to FIGS.7 and 8. As shown in FIG. 7, reactive members are added to the ink andthe base layer in advance. The reactive member in the ink and that inthe base layer contact with each other to start gelling reaction,thereby setting the ink. The ink forming droplet 8 includes in advancedonor 14 corresponding to the reactive member, and base layer 11includes in advance acceptor 15 corresponding to the reactive member. Inthe case of FIG. 7, droplet 8 including donor 14 lands on base layer 11which includes acceptor 15, then donor 14 and acceptor 15 react witheach other, which produces reacted donor 16 and reacted acceptor 17.Reacted donor 16 and reacted acceptor 17 start gelling the ink. As shownin FIG. 7, after the gelling, there still remain unreacted donors 14 andunreacted accpetors 15 in landed droplet 13. Those unreacted donors 14and acceptors 15 remained in the droplet 13 can increase the thickness,volume, amount and weight of landed droplet 13 as shown in FIG. 6.

Next, the theory of reducing uneven print is demonstrated with referenceto FIG. 8, which illustrates a case where a reaction between organiccomponents is used. In this fourth embodiment, an organic componentadded to the ink and an organic component added in advance to the baselayer react with each other, which starts gelling and sets the ink. InFIG. 8, among organic substance 18 such as resin or dispersant, resin 18a included in droplet 8 contains donor 14 as a functional group. Organicsubstance 18 b included in base layer 11 contains acceptor 15 as afunctional group. In this embodiment, droplet 8 lands on burn-off baselayer 11 to form landed droplet 13. Then donor 14 of resin 18 a indroplet 13 and acceptor 15 of organic substance 18 b in base layer 11produce gelling reaction.

Exemplary Embodiment 5

In the fifth embodiment, plural inks are used, i.e., one jet-inkcontaining non-burn-off material (hereinafter called non-burn-off ink)and another jet-ink containing burn-off material (hereinafter calledburn-off ink). A given pattern is printed on one base using thenon-burn-off ink and the burn-off ink alternately. This operation isrepeated plural times to form a three-dimensional structure. Accordingto the present invention, the members reactive with each other (e.g.,donor and acceptor) are added to the non-burn-off ink and the burn-offink respectively, so that the inks start gelling upon contacting witheach other, which eliminates a step of drying the inks. Thus the inks donot mix with each other and are free from draining or oozing, and canform a given three dimensional structure. The structure thus formed isdried and baked, whereby the part formed by the burn-off ink is burntoff and volatilized. The non-burn-off material in the non-burn-off inkcontained in the three dimensional structure remains as it is and issintered to form the given structure.

FIG. 9 illustrates a case where a reactive member is added to thejet-ink to form a three dimensional structure. In FIG. 9, droplets 19 tothe base layer form burn-off layer 11 after the landing. Droplets 8jetted from the inkjet apparatus (not shown) land and form electrodepattern 1. Droplets 19 jetted from the inkjet apparatus also land andform burn-off base layer 11. In this embodiment, droplets 8 and droplets19 contact with each other after the landing and start gelling asdiscussed in the previous embodiments, therefore, the patterns do notooze to each other. On top of the patterns thus gelled, new patterns arefurther formed, as shown in FIG. 9, with droplets 8 and 19 jetted fromthe inkjet apparatus, thereby forming a three dimensional structure. Thestructure thus formed is finally dried and baked, so that the partformed by droplets 8 remains as the three dimensional structure and thepart formed by droplets 19 is burnt off. The three dimensional structurecan be thus manufactured. Particularly in this embodiment, just beforethe baking, burn-off base layer 11 as a protective member protects thethree dimensional structure until it is baked. The three dimensionalstructure can be also formed being buried in the base layer. Thereforeif more complicated and elaborate work is required in a threedimensional structure, this method can manufacture it precisely and inaccurate dimensions.

The baking of a three dimensional structure sometimes causes burningshrinkage in the structure by 10 to 50% depending on a baking condition.In such a case, the three dimensional CAD pattern is revised responsiveto the shrinkage ratio. Particularly in this embodiment, molds are notused, and three dimensional structure can be directly formed by theinkjet. Thus only a change of dimension in the three dimensional CAD canrevise a burning shrinkage ratio, so that a highly accurate structurecan be formed in a short time.

Material hard to be sintered such as ceramic members including aluminaor zirconia can be added to the burn-off base layer, so that a threedimensional structure is not loosen or deformed during the baking.

Exemplary Embodiment 6

In the sixth embodiment, non-burn-off materials different from eachother are put respectively into different inks reactive with each other,and a given pattern is formed on a single base using these inks. Thisoperation is repeated plural times to form a three dimensionalstructure. Particularly in this embodiment, reactive members with eachother are put in the respective inks, so that the inks still wet do notmix with each other and are free from draining or oozing. As a result, athree dimensional structure still wet or in gel status can be formed.The three dimensional structure thus formed is dried and baked, wherebythe three dimensional structure made of the non-burn-off materialsdifferent from each other is formed.

FIG. 10 shows a sectional view of the three dimensional electroniccomponent produced in accordance with the sixth embodiment. As shown inFIG. 10, ink (not shown) for ceramic lands and forms ceramic 20, ink(not shown) for electrode lands and forms electrode 21, and ink (notshown) for via hole lands and forms via hole 22. The three dimensionalstructure thus formed is then baked at a given temperature, and externalelectrodes are formed before it is completed as a given electroniccomponent. In the sixth embodiment, donors or acceptors are addedindividually to the respective inks for ceramic, electrode and via hole.Thus those inks are gelled to avoid mixing with each other, and arequired printed structure can be formed.

As the ink for forming ceramic 20, the following materials such asglass, dielectric body, magnetic body, or ceramic can be used as far asthey are oxide.

Exemplary Embodiment 7

In the seventh embodiment, the reactive member is described, which is tobe used for forming a three dimensional structure using ink and burn-offbase layer, or plural inks. In this embodiment, donors are added to inkand acceptors are added to the burn-off base layer. The donor andacceptor are reactive with each other. At the moment when the inkincluding the donors lands on the base layer which includes theacceptors, the donors and acceptors react with each other. Thus thelanded ink is prevented from draining. As a matter of course, when theink contains acceptors and the burn-off base layer contains donors,draining of the ink is also prevented. In this embodiment, for thepurpose of simple description, the reactive member contained in the inkjetted from a printer head is called donor, and the reactive membercontained in the ink accepting side is called acceptor.

Exemplary Embodiment 8

In the eighth embodiment, a salting out member is used in donors andacceptors that produce gelling reaction. First, anionic PVA is dissolvedin water, and this water solution is applied and dried as a burn-offbase layer of anionic material. To be more specific, PVA is modified bycarboxylic group, meanwhile this member is purchased from KURARE Inc.The ink is made of a given powder with additive of nonionic or cationicmaterial. Then an inkjet apparatus jets the ink onto the base layer ofanionic material to form a given pattern. At the instant when the inklands on the base layer, the ink reacts on anionic resin of the baselayer and starts gelling. In this case, the water solution of anionicPVA is made of commercial anionic PVA in a quantity of 1 to 50 g,dissolved in the pure water of 100 g. If the amount of PVA is less than1 g, the concentration of resin solution is too low and a necessary filmthickness sometimes cannot be obtained. If the amount of PVA is not lessthan 50 g, the viscosity of the resin solution is too high and it ishard to apply the solution. In the case of thinning the base layerthickness not more than 0.1 micron, or increasing the thickness of theink not less than 10 micron, the absolute amount of the anionic resincontained in the base layer eventually becomes small, which lowersreactivity with the ink. In such a case, organic acid can be added tothe anionic base layer, thereby strengthening the gelling reaction. Forinstance, dissolve anionic PVA available in the market of 1 g to 40 ginto pure water of 100 g, and dissolve organic acid such as citric acidor lactic acid of 0.1 g to 10 g therein. The water solution thusproduced is applied and dried to be the burn-off base layer. Other thananionic resin, formic acid, acetic acid, oxalic acid, citric acid andlactic acid can be used as organic acid. One of those organic acids onlyor combined with other water-soluble resin can produce a similarreaction. An effective amount to be added is 0.1 g to 10 g. A molecularweight of the organic acid is preferably 100 or more than 100. If themolecular weight is less than 100, the organic acid added to the baselayer sometimes volatilizes and disappears automatically. If the organicacid is added to the anionic PVA, it sometimes causes gelling reactionto the PVA instead. To prevent this problem, it is preferable to addweak organic acid to weak acid water-soluble resin. Strong acid and weakacid are classified based on functional groups, and relevant literaturesavailable in the market tell the classification.

As anionic materials, it is preferable to select the material includingfunctional group such as NH—, OH—, CO₃—, HCO₃—, CH₃CO₂—, and the like.Dispersant, resin of phosphoric acid base, S—, HS—, or HSO₄— tends toattach to powder surface, and they are very useful as additive to theink because those materials can increase dispersion and stability of theink. Be cautious that an amount of those additive is preferably lessthan 1 g because too much additive would damage the oven during thebaking or degrade the reliability of the product.

In the case of using water-soluble resin as burn-off base layer 11, thefollowing materials can be used: polyvinyl acetal resin, polyvinylalcohol resin, methyl cellulose resin, carboxy-methyl cellulose resin,hydroxy-propyl cellulose resin, and acrylic resin. The resins discussedabove are added to one of jet-ink or the base layer, and organic acid ororganic base is added to the other one, thereby producing the gellingreaction.

When metals such as nickel, in particular, is used in ink with resin ordispersant of carboxylic acid, the ink thus produced becomes weak acid,and nickel sometimes dissolves as ion to form supernatant liquid (nickelion) of blue-green color. If the ink's pH is greater than 3, nickeldissolves a little and no serious problem occurs; however, if the pH isnot more than 3 (particularly not more than 2), the nickel dissolves alot, which degrades the properties of a laminated ceramic capacitorhaving an internal electrode made of nickel.

Exemplary Embodiment 9

In the ninth embodiment, a combination of acceptors and donors employsthe members that cause gelling reaction. The difference in pH of aburn-off base layer from that of jet-ink is used to produce gellingreaction. For instance, first one uses acid of less than pH 7 and secondone uses base of pH 7 or greater than pH 7, and acid-base reaction canbe used. In a case of using an acid substance or a basic substancehaving a small molecular weight, gelling reaction does not occur and theink stays water-soluble status. On the contrary, in a case of using thesubstance having a great molecular weight, e.g., more than 1000,neutralization reaction between the acid and base lowers the dissolubleconcentration of that substance. Thus the substance cannot be hydratedcompletely, and parts of the substance separates out (deposits) ingelled status in the solvent. Meanwhile, a pH meter available in themarket tells whether the ink or base layer is acidic, basic or neutral.Ink per se is set in a centrifugal separator, and fine particles in theink precipitate, the supernatant liquid thus obtained can be used formeasuring pH. To know the pH of the burn-off base layer, dip the baselayer into pure water, and put it in a centrifugal separator to obtainsupernatant liquid, which is used for measuring the pH. The super-natantliquid thus obtained can be concentrated upon request.

The inventors find that the difference in pH of the burn-off base layerfrom that of the jet-ink is preferably not less than 0.5 (morepreferably not less than 1). When the difference in pH is not less than0.5, polymeric materials, of which molecular weight is at least 1000,preferably more than several thousands or more than several tenthousands, can cause gelling reaction because of the difference of acidand base of their functional groups.

Exemplary Embodiment 10

In the tenth embodiment, a combination of acceptors and donors employsthe members that cause chemical reaction. A selection of acidic orneutral burn-off base layer with respect to basic ink causes similarchemical reaction to what is discussed in the previous embodiments. Forinstance, dispersant including amino group or cationic dispersant ismixed into the ink to produce basic ink. Basic water-soluble organicsolvent of various amines or dimethyl formanide (DMF) can be added tothis ink, so that dispersibility and stability of the ink improve andalso reactivity of the base layer increases.

Next, the case where amine is used as basic material is detailedhereinafter. Amine or amide used in one of the ink or the burn-off baselayer can cause gelling reaction similar to that discussed in theprevious embodiments. Meanwhile primary amine refers to RNH₂, secondaryamine refers to R₂NH, and tertiary amine refers to R₃N. Any amines canbe used in the present invention. R represents hydrocarbon. As foramide, any amide of primary amide, secondary amide and tertiary amidecan be used in the present invention. For instance, ethanol amine can beused in either one of the ink or the base layer. Gelling reaction canstarts when a basic material is used in either one of the ink or thebase layer. In any cases, it is preferable to use pH not more than 12.If pH is 12 or more than 12, human skin can be corroded depending onhandling the materials.

Exemplary Embodiment 11

In the eleventh embodiment, a combination of acceptors and donorsutilizes solidifying reaction of protein. The present invention canutilize the solidifying reaction of protein. This reaction has been usedin manufacturing “tofu” (bean curd). In the present invention, simpleprotein such as albumin and globulin, or gelatin, peptone, keratin,collagen can be used as protein.

Various proteins are available at a reasonable cost due to the recentprogress of biochemistry, and proteins excellent in absorption to powdersurface or binder component in ink are also available. In other words,protein component is mixed with ink, and setting agent such as gluconicacid is mixed with the burn-off base layer, so that the ink startssolidifying upon contacting of the ink and the base layer.

Further, biochemical aggregation, similar to the foregoing reaction andone of antigen-antibody reactions, can be used. This reaction refers toa phenomenon where hematid (red blood cell) in blood aggregates due toantibody reaction to antigen. In this embodiment, antigen or antibodybonded to the surface of synthetic resin particles can be used insteadof putting hematid in the ink, so that high sensitivity of arregation isutilized. Thus a very little amount of such material can be useful inthe present invention. Such materials are available at reasonable coststhanks to the recent progress of biochemistry. Materials excellent inabsorption to powder surface or binder component in ink are alsoavailable.

Exemplary Embodiment 12

In the twelfth embodiment, a combination of acceptors and donorsproduces dehydrating reaction. Methanol, ethanol or other higher alcoholor acetone can be added in advance as dehydrating agent to burn-off baselayer 11 in order to gel the ink mixed with water-soluble resin such aspolyvinyl alcohol. At the instance when this water-soluble ink lands onbase layer 11 including the dehydrating agent, the water component inthe ink is removed and parts of the hydrated ink materials separate out(deposit) or thicken (body up). Thus the landed ink can keep its shapeaccurately. The reaction between the burn-off base layer and the inkproposed in the present invention can be satisfied with accompanying thegelling or the increase of viscosity. Therefore, milk commerciallyavailable can be used in the ink, and vinegar commercially available canbe used in the burn-off base layer. It is generally known that when milkmixes with vinegar, the milk is gelled. In this case, the componentemulsified and dispersed in the milk is broken. The present inventioncan utilize such agglutination reaction of emulsion.

Exemplary Embodiment 13

In the thirteenth embodiment, non-water-soluble resin is emulsified inwater, and this resin is used instead of water-soluble resin. Forinstance, non-water-soluble resin such as polyvinyl-butyral isemulsified in the water with emulsifying agent. This product iscommercially available. Such emulsifying results in a nonionic product,a cationic product or an anionic product depending on an emulsifyingagent. A use of polarity difference in those emulsions thus obtained cancause gelling reaction similar to those discussed in the previousembodiments. For instance, when nonionic emulsion is mixed with anionicemulsion, the emulsions are broken and resin component separates outinto the water solution. This kind of gelling reaction or separatingreaction can be produced by, e.g., adding organic acid, organic base, orwater-soluble anionic resin or cationic resin to nonionic emulsion.

Therefore, one of the emulsions discussed above is added to either oneof the ink or the burn-off base layer, and the material reactive to thisemulsion is added to the other one (ink or base layer), so that settingreaction or solidifying reaction occurs in colloid solution. Thosereactions (gelling, separation of resin, increasing viscosity,precipitation) make an ink-shape printed by inkjet more precisely.

In a case of using latex resin or emulsion resin in burn-off base layer11, a particle diameter of those materials is preferably not more than 5microns (more preferably not more than 2 microns). If emulsion particleshaving diameter of not less than 5 microns are used in the ink, theprinter head tends to clog, and when the particles are used in the baselayer, they cause uneven thickness of the base layer. Thus the particlediameter not less than 5 microns is not suitable for manufacturingelectronic components.

As discussed above, non-water-soluble resin can be used in the presentinvention, namely, water-soluble resin such as polyvinyl alcohol is usedas emulsifying agent or protective agent to form emulsion. Anionicmaterial containing carboxyl group can be used as emulsifying agent, sothat anionic emulsion resin is produced. The anionic emulsion resin thusproduced induces a kind of gelling reaction upon contacting withcationic resin or organic base, cationic emulsion or nonionic resin.

A use of emulsion reduces amount of organic solvent used in themanufacturing process of ink or burn-off base layer. Therefore, in themanufacturing site, safe and environmental friendly manufacturing freefrom fire regulation can be realized.

Exemplary Embodiment 14

In the fourteenth embodiment, physical gel is used as the donor andacceptor of the present invention. The physical gel in this embodimentrefers to the gel formed by physical bridge such as hydrogen bonding orionic bonding between polymer molecules, or chelate formation. Such gelscan be produced by varying heat, types of solvents, ion concentration,or pH. The water solution of agar or gelatin is turned into gel bylowering the temperature, and turned into sol by raising thetemperature. Such a reversible gelling reaction can be used in thepresent invention.

As discussed above, two types of polymer electrolytic solutions havingopposite electric charges to each other are mixed, thereby producing gelcalled polyion complex gel. Such a gel is subjected to various factorsincluding types of solvents, ion concentration, pH, polymerconcentration and the like; however, optimization of those parametersproduces a structure that can maintain more precise three dimensionalshape. For instance, polycation and polyanion in an equal quantity areadded to the ink and the burn-off base layer respectively, therebyproducing neutral gel in the landed ink.

Polycarboxylic acid such as polyacrylic acid or strong acid polymer suchas poly(styrene sulfonic acid) is bonded with alkaline-earth metal,thereby also synthesizing gel. Such bonds is not a direct bond betweenmetallic ion and ligand, but the bond is formed via hydration-ion,therefore, gelled ink is obtainable with ease. In those reactions,optimization of molecular weight and concentration of polymer, types ofsolvents, salt concentration can produce a suitable set condition of theink for respective applications.

The gels such as agar, gelatin, agarose, alginic acid, carrageenan andthe like are the products of sol-gel reaction due to their helixformations. In those cases, the ink made of gelatin water solution isheated and jetted from an inkjet apparatus to a cooled sheet, then thelanded ink can be set. In a case of gelatin, it is practically usefulbecause its sol-gel transformation tends to occur around 25° C. In acase of electrolytic polysaccharide such as alginic acid, adding calciumion helps producing gel. Thus polysaccharide or calcium can be added toeither one of the ink or the burn-off base layer, or vice versa can makethe ink set suitable for respective applications. In a case of calcium,it hardly affects adversely to the finished product even the calcium isbaked. Agar and agarose can be also used.

In the present invention, the gelling indicates a status where fluidityof ink lowers. For instance, a combination of protogenic polymer such aspolyacrylic acid, polyaryl amine, polyvinyl alcohol, with protophilicpolymer such as polyethylene glycol, polyvinyl pyrrolidone can producegel. In a case of using such polymer gel or polymer complex, thepercentage composition of the protogenic polymer and protophilic polymercan be adjusted as approx. 1:1, so that stable gelling reaction isexpected. Optimization of polymer concentration, ion concentration, andpH upon request can realize the ink-set condition suitable for therequest.

In a case of polymer having ligand, which can form complex as sidechain, such as poly(carboxylic acid), polyol and polyamine, addingpolyvalent metal ion can help producing ion. For instance, polyvinylalcohol in copper acetate aqueous solution is used as the burn-off baselayer, and the ink including NH₃ functional group lands on this baselayer. Then the landed ink becomes gel instantaneously. Reaction ofhydro-colloid such as alginate, mannan with bivalent metal ion such ascalcium ion also produces gel. In a case of such gel, chelator such asethylene diamine tetra-acetate (EDTA) is added so that calcium ion isremoved, whereby the gel turns into sol again. Arbitrary control of thisgelling-soling reaction can optimize manufacturing methods of variouselectronic components suitable for respective applications and products.

Xanthan gum of polysaccharide, which is used as bodying agent or gellingagent in food, can be used in this application of the present invention.Hyaluronic acid can be also used in this application because of its highwater absorbing property. Curdlan of polysaccharide is not water-solublebut can be gelled at 54° C. and, at 80° C. it is further gelledthermally irreversible, thus it can be used in this application. Asdiscussed above, in the case of natural polymer, various gellingreactions are available. For instance, starch, agar, carageenan, andgelatin can be gelled by hydrogen bonding (gelling by cooling inparticular). Adding polyvalent metal ion to alginic acid, pectin,carboxymethyl cellulose, or mannan can produce gel. Methyl cellulose orhydroxy-propyl cellulose can be gelled by its hydrophobic interaction(gelled by heating, e.g., alkyl side-chain of carbon number 6, 12, 16 isadded in a quantity of several % to hydroxy-propyl cellulose, thengelling reaction occurs). Xanthan gum or hyaluronic acid can be gelledby cooling. Curdlan can be gelled by heating. Those reactions can beused in the present invention. Hyaluronic acid made by cosmeticmanufacturers or food manufactures in Japan is available. Theymanufacture this acid by fermentation method or extract it from cock'scomb.

In a case of protein, gelatin or collagen can be gelled by cooling. Eggwhite albumin, soybean protein or casein can be gelled by heating (orprotein association). Fibrin, elastin or keratin is possibly gelled bycovalent bond. Those gelling reaction can be also used in the presentinvention.

Various materials developed for disposal diapers, sanitary napkins,skincare, and hair-care can be also used. Polymer aggregating agent(electrolytic polymer that aggregates fine particles dispersing inwater) can be used in the burn-off base layer, so that fine particles ofthe metal or the oxide contained in the ink landed on the base layer canbe flucculated or precipitated for setting the ink. For such anapplication, nonion or anion polymer, cationic polymer and amphotericpolymer are commercially available. They can be used in the presentinvention responsive to respective applications.

The jet-ink used in the present invention preferably contains at leastone of metal powder, dielectric powder, glass powder, ceramic powder,ferrite powder, oxide powder in a quantity of 1 to 80 weight %. If thecontent is less than 1 weight %, a predetermined electrical propertiessometimes cannot be obtained after baking. If the content is not lessthan 81 weight %, ink sometimes clogs the inkjet printer. A particlediameter of those powder is preferably ranges from 0.001 μm to 10 μm. Ifthe diameter is less than 0.001 μm, pieces of powder become too small,which invites a higher cost, and sometimes a given electrical propertycannot be obtained. If the diameter is not less than 12 μm, the powderpercipitates or flucculates in the jet-printer, which eventually clogs.The viscosity of jet-ink is preferably not more than 2 poise. If theviscosity is not less than 2.5 poise, a jet printer is hard to jet theink, and jets the ink in dispersed directions. In a case of jetting theink in dispersed directions, landing accuracy of the ink on the sheetdegrades, so that the inkjet cannot form a precise pattern.

Reactive material or organic material containing functional groups suchas carboxylic acid, carboxyl group or amine, they are to be donors oracceptors proposed by the present invention, is preferably contained inthe ink or the burn-off base layer in a quantity of not less than 0.01weight %. If the content is less than 0.01 weight %, the ink set statusrequired in the present invention sometimes cannot be obtained.

When the burn-off base layer is to disappear, the thickness ispreferably not more than 20 μm. If the thickness is not less than 25 μm,the pattern formed on the base layer slips or deforms when the baselayer disappears. In the case of reaction produced by difference in pH,the difference is preferably not less than 0.5. If the difference isless than 0.3, the landed ink sometimes cannot be gelled.

The gelling reaction proposed in the present invention is a phenomenonoccurs between plural jet-inks, or jet-ink and a burn-off base layer, orjet-ink and a substrate supposed to be printed. The gel per se ispreferably an organic substance to be burnt off. However, as discussedabove, metal, oxide, or metal ion thereof contained in the jet ink orthe burn-off base layer reacts with another organic substance after thelanding, and they can be gelled.

Thus, in accordance with the present invention, an ink pattern can beformed also on the surfaces of low ink acceptability with least oozingand dripping. The low ink acceptability surfaces of metal sheet, etc.can be provided with a high-precision ink pattern using the method ofpresent invention. Furthermore, an ink pattern can be formed on thesurfaces of cylindrical substance and other three-dimensional items withleast oozing and dripping.

The ink pattern provided in accordance with the present invention is apattern in gel state produced as the result of reaction between the baselayer and the jet-ink ink landed on the base layer. Therefore, thepattern in gel state can be used also as the resist pattern (includingthe resist pattern for etching) employed in the manufacturing ofelectronic components. Various types of electronic components may bemade available by taking advantage of these ink patterns or resistpatterns.

Now, a method of manufacturing electronic components is described inaccordance with Exemplary Embodiment 15.

Exemplary Embodiment 15

A method of manufacturing a magnet roll used in printers which make useof toner is described in exemplary embodiment 15. Magnet roll is anelectronic component, also called as development roll, developmentsleeve, toner carrier.

In the recent laser printer business, users demand the printed image ofhigher quality. Conventional printers use magnet rolls made of metalpipe having sand-blasted surface. The conventional magnet rolls,however, are machined at the surface with cutting and the like devicesto be finished to a high dimensional accuracy, and then the surface isroughened by sand-blasting to provide a roughness for the sake ofimproved toner holding. Such being the conventional situation, a magnetroll of the higher mechanical precision level has been requested. Thiswould be realized eliminating the sand-blasting process.

An exemplary method of manufacturing a magnet roll is described inaccordance with the present invention, referring to FIG. 12 through FIG.14.

FIGS. 12A, 12B and 12C are perspective views used to show how a resistpattern is formed on the surface of a metal pipe. In FIG. 12A, referencenumeral 23 indicates a metal pipe, of which the mechanical precisionlevel has been raised through the cutting, grinding, etc.

FIG. 12B is a perspective view showing metal pipe 23 coated at thesurface with base layer 11. Base layer 11 can be provided by means ofdip coating, inkjet printing, spraying, etc.

FIG. 12C shows how a pattern is printed by droplets 8 jetted from inkjetapparatus 7. Droplets 8 form a certain resist pattern 24 after theylanded on base layer 11.

As the arrow marks in FIG. 12 indicate, inkjet apparatus 7 and metalpipe 23 change their positions respectively. Resist pattern 24 is formedon the entire surface of the metal pipe by shifting inkjet apparatus 7to and fro, while revolving metal pipe 23, in the respective directionsas indicated with arrow marks. The traveling distance of inkjet 7 andthe revolution angle of metal pipe 23 may be determined to an optimumaccording to respective applications.

Now, detailed description is made referring to FIG. 13.

FIGS. 13A, 13B and 13C are cross sectional views used to show how resistpattern 24 is formed on the surface of metal pipe 23. FIG. 13A shows howinkjet apparatus 7 jets droplets 8 for the printing.

FIG. 13B shows that droplet 8 jetted from inkjet apparatus 7 lands onbase layer 11 to form resist pattern 24. FIG. 13B corresponds to a crosssection of FIG. 12B.

FIG. 13C shows the state after base layer 11 is removed. In FIG. 13C,reference numeral 25 indicates opening 25, at the bottom of opening 25the surface of metal pipe 23 is exposed uncovered. When metal pipe 23 ofFIG. 13B is washed with water, for example, non-gelled part of baselayer 11 is selectively washed out. Opening 25 is thus provided. Resistpattern 24 is created by gelling reaction between landed droplet 8 andbase layer 11, and resist 25 pattern is not washed out and stays there.

Resist pattern 24 is a gelled compound of droplet 8 and base layer 11.Instead, resist pattern 24 may be formed with either a mixture ofdroplet 8 and base layer 11, or a compatible blend material of droplet 8and base layer 11. Or, the resist pattern may be formed of a substancecreated by gelling reaction caused after these mixture and compatibleblend material were heated. It is useful to heat resist pattern 24. Heattreatment reinforces the film strength and the withstanding propertyagainst etching solution.

Now, description is made on a case where resist pattern 24 is formed bycompatible blending base layer 11 and droplet 8 landed on base layer 11together, or mixing them, and then heating them to cause the gelling. Analkaline water-soluble resin of copolymerized isobutylene and maleicanhydride can be used for a compound which brings droplet 8 and baselayer 11 into a chemical reaction or mutual reaction. The alkalinewater-soluble resin can be made into water-soluble state by having itreacted with sodium hydroxide, ammonia.ammine, etc. Alkalinewater-soluble resin is an organic substance that burns-off at atemperature not lower than 300° C.

First, as shown in FIG. 12B, base layer 11 of water-soluble resin isformed on the surface of metal pipe 23. Next, as shown in FIG. 12C, awater-soluble ink containing alkaline water-soluble resin is ejectedonto the base layer from inkjet apparatus 7 in the form of droplet 8. Inthis way, resist pattern 24 made of a compatible blend substance, or amixture, of base layer 11 and droplet 8 is formed on the surface ofmetal pipe 23. The resist pattern 24 becomes insoluble after itunderwent a heat treatment not lower than 120° C. This is causedbecause; as the result of heat treatment, the alkaline water-solubleresin and alcohol group, ammine group, epoxy group contained in thewater-soluble resin of base layer 11 react to cause gelling, or becomesinsoluble.

FIGS. 14A, 14B and 14C are cross sectional views and perspective viewused to show how the surface of metal pipe 23 is etched with resistpattern 24 used as the etching resist.

FIG. 14A is a cross sectional view which shows a state after the surfaceof metal pipe 23 is etched with resist pattern 24 used as the etchingresist. In FIG. 14A, reference numeral 26 indicates a recess created asthe result of etching of surface of metal pipe 23.

FIG. 14B is a cross sectional view showing how resist pattern 24 isremoved. Resist pattern 24 can be removed by immersing it in warm waterof approximately 60° C. through 90° C., or by applying a high pressurejet of warm water. For the purpose of removing resist pattern 24, arubbing operation using a resin-made brush, etc. may be useful.

FIG. 14C is a perspective view of metal pipe 23 provided at the surfacewith recesses to form a certain specific pattern. By inserting a certainspecific magnetic member at the central part or other place in theinside of metal pipe 23, a magnet roll is completed to be incorporatedin a printer.

Exemplary Embodiment 16

In the embodiment 16, description is made on the improvement in thequality of images printed with a magnet roll of embodiment 15 revolvingat high speed.

In the recent laser printers, users demand higher printing speed. Forthis purpose, amount of toner transfer per unit time by a fast revolvingmagnet roll has to be raised. However, recesses 26 of conventionalsand-blasted magnet rolls have smooth inner wall surface. So, tonersometimes slips on the smooth surface of the inner wall of hollow 26.When magnet roll is driven at a high revolution speed, the amount oftoner transfer per unit time sometimes decreases.

Therefore, a magnet roll which does not allow the toner to make slippingon the inner wall surface of recess 26 even when it is revolving at highspeed has been requested.

FIGS. 15A and 15B illustrate how toner slips on the inner wall surfaceof recess 26, and how to prevent it.

FIG. 15A is a cross sectional view of recess 26 used to show how tonerand the carrier slip on the smooth surface. FIG. 15B is a crosssectional view used to describe how toner and the carrier are heldretained without slipping on the roughened inner wall surface of recess26.

In FIG. 15A, reference numeral 27 a indicates the inner wall surfacehaving a smooth surface. Numeral 28 indicates toner, while numeral 29indicates the carrier. Toner 28 is as small as several microns in thediameter. So, toner 28 and carrier 29 sometimes slip on the smoothsurface of inner wall 27 a along the directions of arrow marks.

FIG. 15B shows how roughened surface 27 b of recess 26 prevents toner 28and carrier 29 from making slippage. In FIG. 15B, inner wall surface 27b of recess 26 is provided with an irregularity that corresponds tograin diameter of toner 28. Toner 28 is hooked by the inner wall surface27 b's irregularity matching the grain diameter of toner 28; so, theslipping is curbed.

In order to form the irregularity matching toner 28's grain diameter oninner wall surface 27 b of recess 26, it is preferred to take advantageof grain boundary 30 of an alloy metal (e.g. aluminum alloy)constituting metal pipe 23. By choosing an aluminum alloy material whosegrain boundary 30 corresponds to the size of toner 28's grain diameter,an irregularity that corresponds to the grain size of toner 28 can beformed evenly covering substantially the entire area of inner wallsurface 27 b.

Preferred average grain diameter for toner 28 is several microns (morepreferably, not smaller than 1 micron and not larger than 20 microns;further preferably, not smaller than 2 microns and not larger than 10microns). Further preference in this case is that the average graindiameter of grain boundary 30 falls within a range not lower than 10%and not higher than 500% of average grain diameter of toner 28. If itgoes outside the above-described range, the anti-slipping effects mightdeteriorate.

Thus, the slipping of toner 28 can be avoided by takinginter-relationship between the average grain size of grain boundary 30and the average grain size of toner 28 into consideration. Irregularitywhere a protrusion relevant to grain boundary 30 is effectively pushingup on inner wall surface 27 b can be provided by electrolytic etchingprocess. The electrolytic etching can form an irregularity making use ofthe differences in the electro-conductivity and the etching speedarising from grain boundary 30.

The irregularity on inner wall surface 27 b should ideally be consistingof recesses formed after grain boundary 30 fell off as the result ofetching, or protrusions formed of grain boundary 30, or a combination ofthe above recesses and protrusions.

The size of carrier 29 may be greater than that of grain boundary 30.This is because; toners 28 sticking on the surface of carrier 29 arehooked by protrusion of grain boundary 30 protruding on the inner wallsurface 27 b.

As to an etching solution for the electrolytic etching, it is economicalto use a water solution of hydrochloric acid (not lower than 1 wt % andnot higher than 10 wt %). If the concentration of hydrochloric acid islower than 1 wt %, it takes too much time for etching metal pipe 23, ifit is higher than 10 wt % it will need a special care for handling. Asto a material for metal pipe 23, AL (aluminum) is preferred to SUS(stainless steel). In some cases, SUS pipe would face difficulties informing recess 26 by etching, or in providing a protrusion of grainboundary 30 protruding on inner wall surface 27.

It is preferred that metal material of metal pipe 23 is an aluminumalloy which contains at least silicon for not less than 0.20% and notmore than 0.60%, or magnesium for not less than 0.45% and not more than0.90%. Or, an aluminum alloy which contains at least silicon for notless than 0.20% and not more than 0.60%, in addition, magnesium for notless than 0.45% and not more than 0.90%, may be used. The latteraluminum alloy facilitates the ease of realizing a higher precisionlevel after machining it with cutting or grinding tools. Also,controlling the size of grain boundary 30 to be within a range of 5through 30 microns will become easier with the latter alloy. The elementused for the control of grain boundary 30 is not limited to magnesiumand silicon. Instead, it may be controlled by adding iron, chromium,titanium or the like metal components.

Thus, silicon, magnesium, iron, chromium, titanium and the like metalcomponent other than aluminum is separated out to grain boundary 30. Bymaking part of these metal components other than aluminum to separateout actively on inner wall surface 27 b, the function of retaining toner28 from slipping will be ensured.

Exemplary Embodiment 17

A method of manufacturing gravure cylinder, which being one of theelectronic components, is described in accordance with Embodiment 17.The gravure cylinder is one of electronic components used in gravureprinting process widely practiced for production of many types ofelectronic components. Gravure cylinder, or an electronic component, isused not only for printing on paper but it is used in many othersectors, for example, flat panel display (e.g. EL display) which is madethrough the roll to roll process, gravure printing on a green sheet orfilm.

Conventional gravure cylinder is made of a metal column of approximately50 mm through 300 mm diameter, for example, which is plated electricallyon the surface with copper for approximately 100 microns thick. Thecylinder surface is polished and then coated with a photo resist, andthen exposed and developed. Finally, the copper at the surface is etchedto a certain specific pattern, and then hard chromium plating is appliedfor the purpose of protecting the surface of a finished gravurecylinder.

The conventional method of manufacturing gravure cylinders necessitatedphoto resist or the like expensive materials and expensive facilitiesfor the exposure.

In a manufacturing method of the present invention, however, suchexpensive items as photo resist and exposure facility are unnecessary,as described above in the Embodiment 15, etc. Thus, cost of the gravurecylinders can be reduced a step further.

In the case where a resist pattern is formed in accordance with thepresent invention, central portion of the metal column can be removedafter the electroplated copper is etched to a certain specific pattern.In this way, a thin metal tube of approximately 1 mm through 10 mm indiameter having a pattern formed on the surface is provided. The-metaltube may be used for production of electronic components. Or, the metaltube may be incorporated into an electronic component.

Furthermore, a multi-layered circuit board formed of glass epoxy resincontaining three-dimensional wiring, and other types electroniccomponents can be manufactured by making use of a resist pattern 24 inaccordance with the present invention.

1. An ink for an ink jet apparatus, the ink including a component of atleast 0.01 weight %, which reacts with an additive component of organicsubstance included in a base layer formed on a surface of a printingobject to cause gelling, wherein the component is burnt off by baking ata temperature not lower than 300° C.
 2. The ink for ink jet apparatus ofclaim 1 having a thickness of not more than 20 μm and comprisingmaterial which includes one of metal powder and oxide powder, of whichparticle diameter ranges from not less than 0.001 μm to not more than 10μm, in a quantity of not less than 1 weight % and not more than 80weight %.
 3. The ink for ink jet apparatus of claim 1 which forms resistpattern reacting with the additive organic substance contained in thebase layer.